Add tag overview, improve assets

CHDataManagement/Model/Item/ItemId.swift

@@ -0,0 +1,38 @@
+
+struct ItemId {
+
+    let itemId: String
+
+    let language: ContentLanguage
+
+    let itemType: ItemType
+}
+
+extension ItemId: Equatable {
+
+    static func == (lhs: ItemId, rhs: ItemId) -> Bool {
+        lhs.itemId == rhs.itemId && lhs.language == rhs.language && lhs.itemType == rhs.itemType
+    }
+}
+
+extension ItemId: Hashable {
+
+    func hash(into hasher: inout Hasher) {
+        hasher.combine(itemId)
+        hasher.combine(language)
+        hasher.combine(itemType)
+    }
+}
+
+extension ItemId: Comparable {
+    
+    static func < (lhs: ItemId, rhs: ItemId) -> Bool {
+        guard lhs.itemType == rhs.itemType else {
+            return lhs.itemType < rhs.itemType
+        }
+        guard lhs.itemId == rhs.itemId else {
+            return lhs.itemId < rhs.itemId
+        }
+        return lhs.language < rhs.language
+    }
+}